APP-CRITICAL-ERROR on an Aira Heat Pump: Heat pump has stopped working and is no longer providing heat or hot water
Short answer
On an Aira heat pump, APP-CRITICAL-ERROR means: Heat pump has stopped working and is no longer providing heat or hot water. The heat pump stops until the fault clears or is reset. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: Heat pump has stopped working and is no longer providing heat or hot water.
Part involved: system.
Likely causes:
- Not specified.
Is it safe?
| Does the heat pump stop? | Yes |
|---|---|
| Engineer needed? | Yes |
The heat pump stops until the fault clears or is reset.
Resetting itself: no (clears when remedied or removed by a support agent).
Manual reset: Aira support.
What you can check
- Contact Aira customer support; check the heat pump/indoor unit breaker at the consumer unit is on; check system pressure gauge (guide: normally between 1 and 1.5 bar) and report the reading; check outdoor unit is not blocked by debris/snow.
What the engineer will check
- Remote diagnosis; Aira technician site visit for component/refrigerant/electrical faults.
Who to ask for: Aira-employed Clean Energy Technician (R290 heat pump).
Certification: Aira-trained/licensed technician; R290 flammable refrigerant competence for refrigerant work.
What you might notice
Sources
- Aira Outdoor Unit Installation Manual (HPO-AW-6/8-230V-1.0, HPO-AW-12-400V-1.0) ↗ · 1.0 · page p.32 (outdoor manual s.9.2.2); indoor manual 1.0 p.38; Get-to-know p.12 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026